Mazda RX-7 V8 Conversion

If anyone could help me out, I cannot find a good quality site that shows
the parts needed for an RX7 V8 Conversion. My friend is considering this
instead of turboing so please if anyone could link me to some sites that
explain or at least list the parts necessary for this conversion it would
be very helpful.
Thanks

Pythias

Good luck fabricating everything you need. Might as well go 20b.

importluva

No not 20B , Chris has talked about this 1 enough already, just do urself a
favor and go V8

Walt

oh just while you two are talking rotaries, what do the 13b and 20b stand
for? ive searched but just cant find anything on the subject. so can
someone help?

Three excellent sites to work with, V8 is the only way to go with the RX7
if you want cheap, reliable power. Grannys is great!

As to importluva who said why not do the 20b conversion, well, my
girlfriend went that way with her 94 Touring RX7...went through the near
stock 13b-rew as soon as she bought it with what I think a little over 60k
or 80k miles (apex seals WERE 3mm, still didnt hold...had other problems as
well). So we looked into our options, and at the time I found out a page
that sold stock and race prepped rotaries (shanesracing.com) and they had a
nice ported 20b (claimed 340-360 stock horsepower) for $4200 inculding
tranny and complete engine w/ ECU and everything...then the problem arose
of...where to get this thing put in. After many calls to many places, no
shop within hundreds of miles of Atlanta would lend a helping hand, no
place had ever done it. So we had to turn to more resources to find
independent guys, and finally got willing people, only problem was, they
knew it's impossible to find people to put this engine in anything so they
knew what to charge. I got quotes anywhere from $2500-$4000 to fully mount
the engine/tranny and to get it up and running. Most everyone said it's a
tedious process and would take them a few weeks to finish off. Finally we
got a guy who said he would do it for (I think it was) $1700...only problem
was it took him a month to finish the deal. But things went seamlessly, and
the new enigne/tranny have probably 10k miles on them now with zero
problems, although with rotaries problems are always in the future. After
going through the entire ordeal my girlfriend and myself both agreed, an
LS1 would of been a much cheaper, easier and powerful option to go with.
The best thing the RX-7 chassis is great for even all the torque V8's put
out. I remember a friend and I put a Ford 302 into a FC 2nd gen RX7 and it
took the two of us TWO days to take the old and put in the new. Final cost
tally for that swap was well under $1500. The old 1/4 mile was 15.80s and
the new 1/4 mile with a stock 1988 302 from the junkyard with exhaust, new
heads and intake manifold/intake was 13.60s.

thunderbird1100

13b and 20b were engines. The 13b started out life in the FC 2nd gen RX-7
and lived all the way through the FD 3rd gen RX-7 (it was a two rotar,
rotary). The 20b we never got stateside but was in the Cosmos in Japan
(three rotar, rotary).

thunderbird1100

Thank you this helps greatly. I googled and yahooed and couldn't find it
lol, this will also be a work in progress as of he is planning for the
future and if he decides to do it (which I believe he will) it will happen
around next summer. But I also advised him to go with a 302 rather than a
350.

Pythias

Wow. Got to this one late. Granny's uses my car pictures to advertise their
Ford conversion, but my car didnt USE their conversion and they didnt use
my parts. te plans to make teh mounts for my conversion are still on the
V8RX7.com site, however, as well as a small writeup on the build for my
car. their forum has all teh knowledgeable people on doing the
conversion.

They even are organizing a V8 RX7 meet for next spring. So far, nearly a
hundred owners are signed up!

While I won't tell someone that they should do a conversion like this, I
will help them once they've made teh decision. And I will tell of the
reasons that it's better than, say, a 20B conversion. mainly, the 20B is
more expensive by a long shot, ins't as reliable, requires at least as much
work, and does the one thing to the car that the rotary purists claim the
V8 conversion does: ruins the f/r weight balance. The V8 conversion often
improves the balance... (for example, my car had less weight on the nose
than a stock RX7 TII, even though I did nothing to lighten the car).

the engine choices for a swap, in order of desireability, are:

LS1/LS2
LT1
Ford 302
Chevy 350 (old style)

The LSx series and the Ford 302 are the lightest, but are on opposite ends
of teh cost spectrum, with the LS being much more expensive than the 302.
But it's easier to make a lot of power from the Chevy (a couple minor
tweaks on an LS1 and you can have almost 400 hp at the rear wheels).

ChrisV

Thanks ChrisV, my friend said he will be getting job soon and saving up to
do this. I will definitely bookmark the page for when the time comes,
assuming all goes as planned.

Pythias

When installing the 302 in my friend's RX-7 he was telling me the Ford
motor is easier to work on than the Chevy LT1/LS1 motor, is this true? I
wouldn't know as I never have touched both motors really.

thunderbird1100

So heres the thing, I always knew our good friend Chris here was a damn
Genius, so I googled his name (Which Im not gonna release, but found on a
certain website that had to do w/ alternative engines in certain models of
cars) and came up with an impressive list.

Tons of engineering, tons of cars, tons of experimental engineering and
areonautical stuff.

Anyway, the point is, big ups to ChrisV! :thumbs:

Zalight

20b or V8, its a tedious process in any rx7 and the rx8. 20b is rare in the
US, more unique and thats why i suggest it.

importluva

It's definitely cool, but it's vastly more expensive, and it does
negatively affect the weight balance, unlike the V8 conversions.

But is is way cool! One of the guys here at work has a 20B FC convert. Very
fast.

ChrisV

The 302 is a bit easier to work on, due to the front mounted distributor.
And it's physically smaller so it's easier to reach everything. But the
actual difference is probably very minor. These aren't extremely complex
engines. Just the electronics are complex, and those are no more so than
any other car.

ChrisV

20b is a lot more expensive and tedious, first hand learned of that. But
like Chris said, they are very fast...my girlfriend's 94 Touring has
suprised a few 03-04 Cobra drivers.

thunderbird1100

Go to granny's. 13b is a 1.3l twin rotor and 20b in2.0l quad rotor

1nasty5point029 Nov 2012 02:03

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